1. Field of the Invention
Embodiments of the present invention relate, in general, to mobile manipulation coordination and more particularly, to mobile manipulation coordination using proprioceptive and touch-based reactive response behaviors.
2. Relevant Background
Moving from one point to another is not a simple task. For example, it takes an infant close to 18 months before it can easily perceive and traverse its environment. In doing so the child has developed the ability to use its senses to acquire data about the surrounding environment, build a model of sort of the environment and initiate its journey. And while moving from one point to another it continually reevaluates the conditions in which it is moving, making adjustments along the way. When an individual, child or adult, comes across an obstacle a plurality of processes, most of which are subconscious, are undertaken before any action is initiated. Imagine a hiker on a mountain trail. While the goal is clear, follow the trail to the destination, each step involves careful analysis. The terrain is often uneven and surface unreliable. While a visual interpretation may indicate that a stone on which to place the next step is secure, the initial contact with the stone confirms the legitimacy of the prior conclusion. Humans take this type of motion and manipulation of objects for granted as can be appreciated by the challenges that have been faced in trying to reproduce similar behavior in machines.
Traditional approaches to accomplishing something as simple as the height control of a device accept a prior knowledge of the surrounding environment, such as an existing 3D model, or use a downward and/or outward looking range sensor to build up an accurate, persistent model of the surrounding terrain or surface. These approaches then use a joint space iterative model to track the position of the vehicle and arm's 3D position and orientation within this model. The difficulty with this approach is that it requires additional perceptual hardware and inertial sensing solution to track the device's pitch and roll within the model. But humans do not develop a precise model and then operate solely based on that model and the ability to understand its relationship to that model.
For example consider a soldier using a scanning mine detector. Although the operators of such devices are told to keep the sensor head a couple of inches from the ground, many operators have been observed actually allowing the sensor head to periodically brush against the ground as a means to reactively understand and follow the contours of the ground. Many human tasks involve light touch as a means of gaining continuous data by which to modulate movement.
Without a certain level of reactive feedback driven control, the ability of a device such as a robot to use perception and planning is limited by the propensity for an error to exist in the model and an error to occur in the execution of the motion plan. Manipulation of devices today is based on the development and use of a sophisticated 3D model which is used as the primary foundation by which to base movements. Current devices have little information of how they interact with actual environment but rather carefully track their position with respect to a mathematical model. For example, a robot of today could state that one of its arms is 0.5 inches from the modeled surface of an object, but it could not accurately determine whether the arm is actually 0.5 inches from the surface or that the model of the surface fails to recognizes a small outcropping which actually paces the arm within 0.1 inches of the surfaced. Unfortunately, it is this type of perception that has been the primary focus of work in manipulation over the past several years. A challenge remains for a system that can respond adroitly to a surface or an object possessing features that are not properly or correctly captured in a model. These and other challenges of the prior art are addressed by one or more embodiments of the present invention.